Chromosomes, Cell Division, Meiosis and Chromosome

Question 1

Function of Centromere

Answer 1

Hold sister chromatids together

Question 2

Telomeres

Answer 2

Termini of chromosomes

Question 3

Function of Telomeres

Answer 3

Protect chromosome against DNA damage as DNA repair enzymes are able to recognise blunt ends of chromosome

Question 4

How are Okazaki fragments produced

Answer 4

The lagging strand is synthesised discontinuously

Question 5

What is used to join Okazaki fragments

Answer 5

DNA ligase

Question 6

What initiates the assembly of Okazaki fragments

Answer 6

RNA primer

Question 7

End Replication Problem

Answer 7

when the last piece of RNA primer at the 3’ end is removed, the DNA cannot be extended and leaves a gap

Question 8

How is End Replication Problem Solved

Answer 8

Telomerase is used and adds the telomeric sequence to lay out new DNA

Question 9

DNA can only synthesise in which direction

Answer 9

5’ to 3’

Question 10

Do most somatic cells express telomerase

Answer 10

No

Question 11

Do germ cells express express telomerase

Answer 11

Yes

Question 12

Product of Mitosis

Answer 12

2 cells with identical DNA

Question 13

Stages of Mitosis

Answer 13

Prophase
Metaphase
Anaphase
Telophase

Question 14

Prophase

Answer 14

Chromosome becomes visible

Question 15

Metaphase

Answer 15

Spindles fully formed and chromosomes align in the centre

Question 16

Anaphase

Answer 16

Linkage between sister chromatid is broken

Question 17

Telophase

Answer 17

Nuclear membrane is reformed

Question 18

Where do spindle fibres attach to on the centromere during mitosi

Answer 18

Kinetochore

Question 19

Features of Chromatin

Answer 19

Packed with positively charged histones
Compacted into nucleosomes
Core of 8 molecules of histones

Question 20

Solenoid structure

Answer 20

Central structure in which the heterochromatin get assembled to and is 30nm in diameter

Question 21

Heterochromatin

Answer 21

Tightly packed and inactive

Question 22

Eurochromatin

Answer 22

Loosely packed and active

Question 23

Purpose of packaging DNA

Answer 23

Histones (positive) neutralise DNA (negative)
Takes up less space
Inactive DNA folded into accessible region

Question 24

Karyotyping uses what type of stain

Answer 24

Giemsa

Question 25

Acrocentric

Answer 25

Chromosome where the centromere is located very near to one end

Question 26

Submetacentric

Answer 26

Chromosome where centromere is located so that one chromosome arm is longer than the other

Question 27

Metacentric

Answer 27

Centromere is at the middle of the chromosome

Question 28

Length of each band in G-banding

Answer 28

6-8mb

Question 29

FISH

Answer 29

Fluorescent in-situ Hybridisation

Question 30

Meiosis

Answer 30

Process of creating germ cells

Form 2 haploid after 2 successive divisions

Question 31

Cytokinesis

Answer 31

Daughter cells are formed

Question 32

8 Histones

Answer 32

H1, H2A, H2B, H3, H4